1. Field of the Invention
The present invention relates generally to earth-moving vehicles and their use in particularly wet or swampy environments. In particular, aspects of the invention relate to scrapers and similar equipment.
2. Description of Related Art
Scrapers are used for removal and transportation of large amounts of earth. They are typically wheeled and may be towed or self-propelled. A scraper includes a pan which may be lowered to be brought into contact with the earth or raised to be brought out of contact with the ground. The scraper pan contains a bin or receptacle for the holding of earth. The pan features an opening located proximate the ground surface which may be selectively opened and closed. A scraper blade is incorporated into the pan near the opening. When the pan is lowered and the opening opened, the blade scrapes earth into the bin of the pan as the scraper is moved along the surface.
Although conventional scrapers operate reliably on terra firma, they are not generally suitable in areas which are excessively wet or swampy as their weight, particularly when loaded with earth, causes the scraper to become mired.
A particularly difficult operating environment, for scrapers and other vehicles, is the dredge disposal area. In these areas, the spoil from aquatic dredging is placed. Due to the presence of heavy metals and other toxic substances, this spoil is treated as hazardous waste and may be placed in designated disposal sites. Once the spoil is removed from a river bottom or other aquatic site, it tends to expand because it is no longer under pressure. As the spoil expands, it retains significant amounts of water. Due to retained water, the spoil is extremely marshy. Land vehicles are unable to work in a dredge disposal area unaided by placing matting over the spoil or by similar measures. Even with the use of matting, beholds often sink into the spoil and can be recovered only at great cost.
Maintaining a dredge disposal area requires cutting of ditches to drain water from the spoil and then removal of dried soil from the pit. Dredge disposal area maintenance procedures and associated equipment are described in greater detail in U.S. patent application Ser. No. 08/708,648, entitled "Containment Area Process", still pending, and "U.S. patent application Ser. No. 08/706,614 entitled "Positive Drive Winch", still pending, each assigned to the assignee of the present invention and incorporated herein by reference. If capable of operating in dredge disposal areas, scrapers would be ideal pieces of equipment to accomplish removal of the dried spoil.